Premium Material---The coffee maker made with a solid stainless steel interior with double walled construction, double wall vacuum keeps hot water warm and cold water cool. Built in Plunger is 100% BPA free and food safe. Isolation System---The coffee presser built in filter separates the grounds from the brewed coffee, separates the sediment of coffee grounds and coffee,brewing for optimal coffee taste, recommend coarse coffee size about 25g. Insulated Vacuum Construction---Adopt double wall insulated design, keeps your drink hot or cold for 4-6 hours. The stainless steel body provides the durability which makes it ideal for travel. Easy To Clean---Just rinse it under a water tap. The filter mesh can be detached for convenient cleaning. Practical--- The coffee presser self lock lid and silicon seal make this coffee travel mug leak-proof. Great for home, office, camping and outdoors use